Macular Retinal Ganglion Cell Layer Thickness Is Not Reduced in Patients with Obstructive Sleep Apnea

Ganglion cell layer thickening in patients suffering from Obstructive Sleep Apnea-Hypopnea syndrome with long Mean Apnea-Hypopnea Duration during sleep

PURPOSE

To study the effects of mean apnea-hypopnea duration (MAD), a useful indicator of blood oxygenation, on peripapillary retinal nerve fiber layer (RNFL), macular ganglion cell to inner plexiform layer (GC-IPL) and macular retinal thickness in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS).

METHODS

Sixty-five patients recently diagnosed with OSAHS and 35 healthy individuals were enrolled in this cross-sectional study. OSAHS patients were divided according to their MAD values into group 1 with 16 participants (MAD:10-15.5 s), group 2 with 17 participants (MAD:15.5-19 s), group 3 with 17 participants (MAD:19-30 s) and group 4 with 15 participants (MAD > 30 s). The average and sectorial values of RNFL, GC-IPL and retinal thickness were measured by SS-OCT (DRI OCT Triton, Topcon). Intraocular pressure was recorded by Goldmann Applanation and Pascal Dynamic Contour Tonometer (DCT-IOP).

RESULTS

The average RNFL and retinal thickness values were higher in group 4, but did not reach statistical significance. With the exception of the central 1 mm at the fovea, GC-IPL was always thickened in group 4, and significant differences were evident when its average value was compared with group 2 (p = 0.03), its superior and inferior-nasal values were compared with group 2 (p = 0.02, p = 0.006, respectively) and group 3 (p = 0.01, p = 0.02, respectively), its superior-temporal value was compared with group 3 (p = 0.003) and the control group (p = 0.03), and its superior-nasal value was compared with group 2 (p = 0.03), group 3 (p = 0.001) and the control group (p = 0.03). DCT-IOP was significantly positively correlated with the duration of sleep in which oxygen saturation (SaO₂ ) was decreased under 90% (r = 0.359, p = 0.01).

CONCLUSION

We report a novel observation of GC-IPL thickening in OSAHS patients experiencing long MAD, a parameter which incorporates the severity of breathing events during sleep. Higher DCT-IOP was noted with advancing hypoxemia.

Contributions of the Melanopsin-Expressing Ganglion Cells, Cones, and Rods to the Pupillary Light Response in Obstructive Sleep Apnea

Purpose

To investigate the impact of obstructive sleep apnea (OSA) on the contribution of inner and outer retinal photoreceptors to the pupillary light response (PLR).

Methods

Ninety-three eyes from 27 patients with OSA and 25 healthy controls were tested. OSA severity was graded according to the apnea-hypopnea index. PLR was measured monocularly with an eye tracker in a Ganzfeld in response to 1-second blue (470 nm) and red (640 nm) flashes at -3, -2, -1, 0, 1, 2, and 2.4 log cd/m2. Peak pupil constriction amplitude, peak latency, and the postillumination pupil response were measured. The Cambridge Colour Test, standard automatic perimetry, spectral domain optical coherence tomography, polysomnography, and the Pittsburgh Sleep Quality Index were used.

Results

OSA patients have a significantly decreased peak pupil constriction amplitude for blue stimuli at -3, -2, -1, 1 log cd/m2 and at all red flash luminances (P < 0.050), revealing reduction of outer retina contributions to PLR. OSA patients showed reduced peak latency for blue (-2, 0, 2, 2.4 log cd/m2) and red stimuli (-2, 0 log cd/m2; P < 0.040). No significant difference was found in the melanopsin-mediated PLR.

Conclusions

This study is the first to evaluate the inner and outer retinal contributions to PLR in OSA patients. The results showed that the outer retinal photoreceptor contributions to PLR were affected in moderate and severe OSA patients. In contrast, the inner retina contributions to PLR are preserved.

Evaluation of Intraocular pressure, Corneal thickness, and Retinal nerve fiber layer thickness in patients with Obstructive Sleep Apnea Syndrome

Objective:

To evaluate the intraocular pressure (IOP), central corneal thickness (CCT), and peripapillary retinal nerve fiber layer (RNFL) thickness in Patients with Obstructive Sleep Apnea Syndrome.

Methods:

In this prospective study, 103 patients with OSAS (study group) and 37 healthy subjects were enrolled. All participants underwent comprehensive ophthalmic examinations. Mean outcome measures were intraocular pressure by Goldmann applanation tonometry, CCT measurement using ultrasound pachymeter and peripapillary RNFL thickness measured by spectral-domain optical coherence tomography.

Results:

The differences between the mean values of RNFL thickness in all quadrants were similar in both groups and were not statistically significant (p=0.274). The IOP and CCT measurement averages of all patients with OSAS were lower than the control group. However, this difference was not statistically significant. There was no correlation between the apnea-hypopnea index, lowest oxygen saturation (LAST) or Body Mass Index (BMI) and the peripapillary RNFL thickness, IOP or CCT when OSAS group was divided by severity.

Conclusions:

The study results suggest that peripapillary RNFL thickness, IOP or CCT did not differ significantly between OSAS and control groups. We also found no correlation between apnea severity (AHI), lowest oxygen saturation (LAST) and BMI and RNFL, CCT and IOP.

Peripapillary retina nerve fiber layer thickness and macular ganglion cell layer thickness in patients with obstructive sleep apnea syndrome

PurposeTo investigate the association of the severity of obstructive sleep apnea syndrome (OSAS) with peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GC-IPL).Materials and methodsIn this cross-sectional study, 145 patients with OSAS and 40 healthy subjects were enrolled. OSAS patients were further divided into mild (n=50), moderate (n=36), and severe (n=59) OSAS groups according to their apnea-hypopnea index (AHI) values. Spectral-domain optical coherence tomography was used to measure the peripapillary RNFL and GC-IPL thicknesses.ResultsThere was no statistical difference between the RNFL thickness in OSAS and control groups (P>0.05). Both average GC-IPL and minimum GC-IPL thicknesses were significantly lower in severe OSAS group than in healthy controls (P<0.05 for both). There was a significant negative correlation between AHI and both average GC-IPL (r=-0.232, P=0.005) and minimum GC-IPL (r=-0.233, P=0.005) thicknesses.ConclusionsOur study results suggest that although RNFL thickness did not differ significantly between OSAS and control groups, ganglion cell layer thickness in OSAS patients is much lower than in healthy population. Ganglion cell thickness showed a significant correlation with the severity of OSAS.